Value of R gas constant in J mol-1 K-1 is

Explanation

The universal gas constant is 8.314 joules per mole per kelvin, and this is the value to use whenever pressure is in pascals and volume in cubic metres. The figure 0.0821 dm3 atm per mole per kelvin is the same constant expressed for pressure in atmospheres, which is why 0.821 appears as a distractor. Always match the value of R to the units of the other quantities in the problem.